I would start by listening (no pun intended) to your husband, trying to put down on paper all his wishes and dreams about the ideal software for him. And yes, Filemaker is one of the best choices for building such a software.
+1 on FMP as a good software choice.
Years ago (I am a photographer) I got tired of looking for negatives, prints, etc. (Maybe that sounds familiar). I was using FM3 at work, and decided to try to develop a data base for my work. I started with the free "template", as they were called then, for Photo Album, and modified it for my use. Over the years I expanded it in different ways.
It is important, though, what siplus says about identifying any and all of the functionality you'll want - do some reading about how to plan a data base.